Motor vehicle power transmission



June 22, 1937. w. T. DUNN ET 'AL 2,084,578

MOTOR VEHICLE POWER TRANSMISSION Filed May 7, 1954 5 sheets-sheet 1 June 22, 1937.

W. T. DUNN Er AL/ MOTOR VEHICLE POWER TRANSMISSION Filed May 7, 1934 5 Sheets-Sheet 2 ATTORNEYS.

`Iun e 22, 1937. W. T. DUNN r- T A1. 2,084,578

uoToR VEHICLE POWER TRANSMISSION 5 Sheets-Sheet 3 I E /s I /9/ I v my@ E. EL aan? 7. EZ! ENToRs.

A TTORNEY.

June 22, 1937. w. T. DUNN ET Al.

IOTOR VEHICLE POWER TRANSMISSION Filed May 7, 1934 5 Sheets-Sheet 4 y ATTORNEYS.

June 22, 1937. w T DUNN Er AL 2,084,578

moToR VEHICLE PowER TRANSMISSION 5 Sheets-Sheetv 5 Filed May 7, 1934 IN VEN TOR.

L w f m y o pm im r. in

` Patented June 22, 1937 PATENT OFFICE 2,084,578 Moron VEHICLE `POWER y'.laANsMlssloN William'T. Dunn and Augustin J. Syrovy, Detroit,

Mich., assignors to Chrysler Corporation, Detroit, Mich., a corporation of Delaware Application-May 7, 1934, Serial No. 724,434

40 Claims.

This invention relates to power'transmission devices and refers more particularly to improvements in power transmission devices or systems especially adapted for use in connection with motor vehicles, although not necessarily limited thereto.

Our invention, in certain more limited aspects thereof, provides improvements in the drive and control for power transmission systems of the type including the Well-known epicyclic or planetary transmission gear box. With such planetary transmissions, it is customary to arrange the gearing to provide for the desired number of speed ratios between the engine and vehicle drivl5 ing ground wheels fand such gearing is customarily selected and controlled to obtain the desired speed ratio by actuation of any one of a group of transmission gearing controlling clutches usually consisting of reaction brake bands associated with-and controlling the rotation of corresponding drums or similar elements of the various planetary gear trains.

One object of our invention resides in the provision of an improved selector and actuating mechanism for obtaining the several speed ratios provided by the transmission or other speed changing mechanism, the latter preferably being of the planetary gear type although not necessarily limited thereto in the broader aspects of our invention.

A further objectof our invention resides in the provision of improved controls and actuating mechanism for selecting and manipulating the various gear trains of a transmission, particu- 35 larlyA a planetary type of transmission, whereby means is provided responsive to manual control for automatically bringing about a complete 'cycle of gear ratio change. Thus, in one embodiment of our invention we have providedrluid pressure actuating means responsive to operation of manual control for rst releasing the rotary drum of one of the planetary gear trains and then braking another drum associated with thetransmission for establishing a further gear ratio drive for the 45 motor vehicle.

In carrying out the above objects of our invention, we havev provided a common actuator or prime mover which may be of the fluid pressure type for applyingthe necessary force to the brak- 5 ing devices in order to control the rotation of the desired drum of the planetary gearing, a selector mechanism being provided under manual control of the vehicle. driver for selectively causingthe common actuator to apply a braking force to the 55 proper drum. This actuator may be of the iluid (Cl. i4-262) pressure type adapted for operation by oil pressure, air pressure either above or below atmos pheric pressure, or other equivalent systems. We prefer, according to the teachings of this phase of our invention, to provide for energizing the 5 actuator by oil pressure.

A further object of our invention resides in the provision of an improved selector mechanism for use with speed ratio changing mechanisms of the character aforesaid. In one embodiment of 10 our invention this selector mechanism may be operated by fluid pressure under manual adjustment or control, the mechanism further including a novel preselecting means for adjusting the selector mechanism prior to actuation thereof in effecting a speed ratio change in the driving mechanism.

A further object of our invention is to provide improved selector means incorporating a fluid pressure controlling leader valve adapted for manual adjustment by the vehicle operator.

Another object of our invention resides in the provision of improved means for applying the braking force selectively to the various braking devices of the planetary geartrains, this means including a shaft or other operating element adapted for rotary selective adjustment and for reciprocating movement to release and actuate the various braking devices. According to ourv preferred embodiment, this shaft is formed with 3o a plurality of circumferentially and longitudinally spaced sets of rack-like teeth respectively adapted for actuating the braking devices.

A further feature of our invention resides in the provision of improved meansypreferably in the form of an oppositely threaded screw, associated with each of the breaking devices and cooperating with the aforesaid operating shaft to actuate the breaking devices.

Another object of our invention is to provide an 40 `improved preselector arrangement and mechanism operated thereby whereby the vehicle driver may manually select for the desired transmission speed ratio in advance of the speed ratio change, the change in speed ratio preferably occurring, 45 according to this -phase of our invention, in response to operation of-a further manually controlled device such as a foot pedal, for example.

An additional object of our invention resides in the provision of improved fluidv pressure operat- 50 lng means to furnish the necessary power to operate the several'speedratio controlling devices or braking means in the case of a planetary transmission. This power actuating means is preferablyfirransed to release the aforesaid speed ratio controlling devices and also to actuate these devices, although, if desired, other prime mover means may be provided for either the release or the actuation within the broader aspects. of our invention.

A still further object of our invention resides in the provision of improved fluid pressure means for actuating the various transmission controlling devices, this means including means associated with the main pressure cylinder and operating to reduce the amount of fluid necessary to be l pumped to the cylinder to cause actuation of the transmission mechanism and also to effect a very rapid transmission gear change in response to operation of the manual control.

A planetary type of transmission presents a number of advantages over the more conventional sliding gear types of transmissions, and our invention is therefore primarily directed toward planetary types of transmissions and power transmission systems .employing planetary gearing speed ratio controlling devices although, as aforesaid, the fundamental principles of our invention may, if Ldesired, be employed in connection with transmissions of other types including the aforesaid sliding gear types of transmissions. By way of example in connection with the aforesaid advantages of the planetary transmission over more conventional types, it may be noted that the planetary transmission permits gear changes without the necessity of releasing the main clutch between the engine and transmission so as to obtain relatively quick gear changes and faster acceleration of the motor vehicle. This is made possible by reason of the fact that the braking devices associated with the planetary gear trains are, in effect, clutches in that each rotary drum controlling a planetary gear train is frictionally engaged by its associatedbraking means'.

Further objects and advantages of our invention will be apparent from the following detailed description of one illustrative embodiment of the principles of our invention, reference being had to the accompanying drawings, in which;

Fig. 1 is a side elevational view illustrating our power transmission mechanism as a Whole, a portion ofthe clutch casing being broken away toillustrate the main clutch parts, certain parts of the transmission controlling devices being illustrated in cross section.

Fig. 2 is a plan view of the mechanism shown in Fig. 1, portions of the transmission casing being broken away to illustrate the speed ratio gear train controls. i.

Fig. 3 is a sectional elevational view through the transmission illustrating one of the `speed ratio controlling devices and partsassociated therewith, the section being taken along the line Il l--III of Fig. 2.

Fig. 4 is a sectional plan view showing the alignment controlling means associated with the ends of the band operating screws, the section being taken along the line IV--IV of Fig. 3.

Fig. 5 is a detail sectional elevational view ilv lustrating the aligning means for the brake optheir positions occupied during the cycle of speed .ratio change.

Fig. 8 is a detail view of the valve controlled selector mechanism shown in Fig. 7, the parts being shown in their positions of manual ad.e justment prior to the start of the power operated cycle of gear ratio change.

Fig. 9 is a view corresponding to Fig. 7 but showing the parts positioned at the completion of the cycle of gear ratio change.

Referring to the drawings, we have illustrated our invention in connection with a moto-r vehicle drive, this drive including a prime mover or engine A, a portion of which is shown in Fig. l, a main clutch B driven from the engine and a change speed transmission or gear box C driven." from the clutch B. The drive passes from the transmission through a power take-olf shaft I which, as usual, may extend rearwardly of the vehicle to drive the usual ground wheels (not shown).

The clutch B may be of any suitable construction for controlling the drive between engine A and transmission C, this clutch being illustrated in Figs. 1 and 2 in the form of a fluid type having the usual driving and driven cooperating vane members II and I2, respectively. The driving vane member II is carried by the engine flywheel I3, the latter being connected as usual with the rear end of the engine crankshaft I4. The driven vane member I2 is connected at I5 to a flange I6 of the driven shaft I'I, this shaft having a forwardI extension I8 piloted in the rear end of the crankshaft I4. The driven shaft I'I extends rearwardly to drive the power takeoff shaft I 0 through the intermediary of the various gear trains of transmission C.

Where the power means for operating, the transmission is afforded by a uid such as oil under pressure, the pump for placing the oil under pressure is preferably operated from the engine so as to maintain the fluid pressure even when the engine is idling. It is, therefore, preferred to providea pump drive from the driving clutch member II rather'than the driven clutch member I2 inasmuch as the latter may be stationary under certain conditions ofI vehicle operation such as when the vehicle is standing still with the engine idling.

This drive may be provided by reason of a driving sleeve or hollow shaft I9 mounted on the shaft II but rotatable independently thereof. The sleeve I9 has a hub or flange 20 connected at 2| with the driving vane member II of the clutch so that even when the driven vane member I2 is not being operated from the driving member II, the sleeve I9 will be'rotatably driven with the engine crankshaft I4 and flywheel I3. The pump drive from sleeve I9 will be more apparent hereinafter.

We have illustrated a fluid type of clutch B since a clutch of this character has a number of f advantages in connection with a transmission of the planetary( gear type `C. Thus, the fluid type of clutch is desirable in providing a smooth drive for the vehicle through the planetary transmission, relatively high power driving eiiiciency, automatic release of the drive between the engine and transmission when the engine is idling and with the transmission manipulated to establish one .of its driving gear ratio settings, and other wellknown favorable characteristics. We desire to point out that othertypes of clutches may be employed to control the drive between engine A ployed and may be manually operated or autoi natically operated by the well-known commercial type of vacuum clutch releasing mechanism as will be readily understood.

We have illustrated-the change speed transmission C as the epicyclic or planetary type, this general form of transmission being well-known in the art and, as usual, includes a plurality of transmission speed ratio controlling clutches or brakes 22, 23, 24, and 25, these braking devices being respectively adapted to actuate the transmission in its rst speed ratio or low gear, second speed ratio or intermediate gear, third speed ratio or direct drive, and reverse drive.

The typical brake device 25 illustrated in Fig. 3 consists of an outer band 26 which substantially surrounds the drum 21, the band being provided with friction braking material 28 carried by the band and adapted for frictional engagement with drum 21. The band 26 has its ends formed with laterally projecting actuating flanges 29 and 30 positioned adjacent-'each other, means being provided to move the band ends toward eachrother to contract the band 26 for causing the friction material 28 to brake rotary drum 21, the band having suicient inherent resilience to expand away from contact with the drum when the actuating means is relieved at the anged ends 29 and 30. In Fig. 3 the reverse speed ratio braking device 25 is illustrated in its inoperative position whereby the drum 21 is free to rotate through operation of the planetary gear set 3l somewhat diagrammatically illustrated in association with the drum 21. .When the braking device 25 is actuated by contracting the band 26, the` drum 21 is held against rotation, the driven shaft. I0 in such instance being operated through the planetary gearing 3| to provide lthe reverse drive for the motor vehicle.

In order to anchor the band 26 and to substantially equalize the braking forces applied to drum 21 around the periphery thereof so as to substanl tially avoid a tendency toward lateral loading of the drum and planetary gearing transverse tov the axis of the drum, we have provided the band with a circumferentially spaced pair of anchoring flanges 32. The flanges 32 are connected through links 33 with the levers 34 pivotally mounted at 35 with the supporting brackets 36 of the transmission casing 31, the levers 34 being interlocked at 38 so that movement of one of the flanges 32 Will be transmitted through the pivotal levers 34 and the links 33 to the other portion of the band associated with the anchoring device. The links 33 are thus pivotally connected at their opposite ends respectively with the anchors 32 and .levers 34. In order to maintain a yielding tension' in the links and levers to prevent their rattling and also to exert a yielding expanding action on band, 26, we have provided a ribbonlike spring 39 which passes over the brackets 36 and which has its opposite end anchored to the o pivots at the opposite ends of the links 33.

In order to support the brake band assembly as a Whole and to limit outward expansion of thebrake band, we have provided the lugs or stops 26a, 26b which project inwardly of the transmission casing as shown in Fig. 3.

A The third speed braking device 24 is arrange/d for a direct drive through the transmission and differs somewhat from the braking devices 22, 23, and 25 in that the braking device 24 has its rotary element or drum 40 of the cone type adapted for clutching or braking action by frictional engagement with an .axially movable cone clutch member 4I. This cone member 4|. is adjustable by a collar 42 having pins 43 engaged by the yoked end 44 of an actuating lever 45 pivotally mounted by the ball and socket. structure 46 secured by a fastener 41 to the transmissiontranverse housing or casing 48. The opposite end of lever 45 is" formed with gear teeth 49, the purpose of which will presently be more apparent. Forward movement of the cone clutch member 4I is limited by engagement of the lever shoulder 45at with a fixed stop 45b as shown in Fig. 2.

The transmission C has an opening longitudinally along one side thereof, this opening being closed by a removable casing cover 50 removably secured to the transmission through suitable fastenersl as best shown in Fig. 3. The cover 50 is provided with the vertically spaced inwardly extending supporting brackets 52 and 53, these brackets being formed with co-axial openings 54 and 55, respectively. Splined within the openings 54 and 55 are the nuts 56 and 51 and these nuts in tur'n are axially and oppositely threaded to receive the threaded ends 58 and 59 of an operating oscillatory shaft or screw 60.

The shaft 60 extends through openings 6l and 62 respectively formed in the band flanges 29 and 36, these openings preferably having considerable clearance with shaft 60 sogas not to bind on the shaft when the band is contracted and expanded. In order to transmit the thrust of the nuts 52 and 53 to the flanges 29 and 30, we have provided the intermediate washers 63 and 64, these washers having a lower rounded face engaging the edge of the respective openings 6I and 62 so as to facilitate the operation of the band movement and relieve distorting loads at the threaded portions of' shaft 68 during the operation of the band.

The operating shaft 60 of the reverse braking device has its portion thereof intermediate the.

band ends 29 and 30 formed with an arcuate por- 65, the means for oscillating the shaft 6U through the teeth 65 being more particularly hereinafter described.

' In operation of the reverse speed controlling device.v or brake 25 as thus far described, it will be apparent that when the shaft 60 is given a rotary movement, such movement operates through the oppositely threaded ends of the shaft to cause the nuts 56 and 51 to move inwardly toward each other in their splined openings 54 and 55 respectively, this movement acting through washers 63 and 64 to contract the band ends 29 and 38 whereby the reverse drum 21 has its rotation checked for establishing the reverse drive through the transmission. When the shaft 65 is rotated in the opposite direction the nuts 56 and 51 are moved away from each other and the band 26 is expanded to permit the drum 21 to again rotate and thereby relieve the drive through the transmission controlling device 25.

In order to avoid repetition, we have not illustrated all of the details of .the brake operating means associated with the controlling devices 22 and 23, it being understood that 4this operating means is similar to that described in connection with the controlling device 25. For convenience v of reference the operating shaft or screw for the We will next describe the common operating means or actuating element which is adapted fory selective engagement under manual control with the aforesaid gear segments 65, a, 659, and 49 for respectively operating the speed ratio controlling devices 25, 22, 23, and 24 and also for establishing a neutral condition in the transmission.

Referring now particularly to Figs. 2 and 3 the removable transmission side cover 59 is provided with a plurality of suitable bearings one of which is shown at l156 in Fig. 2 for receiving the reciproeating and hscillating rack or actuating shaft D. This actuating shaft D has a series of teeth forming a rack adapted to be brought into operative association with each of the gear segments, these racks'being designated at 61, 68, 99, and 1o. From Figs. 2 andj 3 it win .tey noted that the racks are longitudinally spaced along the shaft D and that .they are also spaced circumferentially of the shaft whereby upon progressive rotation of the shaft only one of the racks will y.

engage its associated gear segment at any time. In Figs; 2 and 8 it willbe noted that the shaft D is positioned so that the third speed rack 19 is in position for operating the third speed gear segment 19 and when the shaft D is moved to the leftI as viewed in Fig. 2 the lever 95 will be rocked on its pivot 99 to move the third speed cone clutch member 91 into engagement with the third speed drum 99 and to thereby arrest rotation of drum 19 and cause the drive to take place through the transmission in the third gear ratio or direct drive. It will furthermore be noted that with the third speed rack 19 in the position illustrated, ythe remaining racks 91, 69, and 99 are free from engagement with their respective associated gear segments 95, 95a, and 65h. From Fig. 3 it will be noted that the shaft Dshas a space 11 longitudinally between the reverse rack 91 and the first speed rack 99,.this space being designated as the neutral space so that when the shaft is positioned with thespace 11 facing the gear segments (when Shaft D is rotated from the position illustrated in Fig. 3) eachof the racks will be free from contact ,with its associated gear segment and the transmission will be in neutral at which time the various braking devices 22, 23, 24, and 29 are released.

In order to selectively rotate the shaft D for selectively engaging the racks thereof with the respective gear segments and also for axially operating the shaft in the various positions of selective adjustment, the following mechanism is provided. The rear end of shaft D is slidably supported in a cylindrical guide 12, the shaft end having gear teeth 13 formed thereon and engaging a circular rack 14. The rack 14 is'guided for vertical movement by a cylindrical guide 15 having an opening in its rear wall to receive the quadrant gear 15.

The gear 19 as best shown in Fig. '1 operates in a housing 11, the gear being fixed to a shaft 18 (see Fig. 2) which extends outwardly to receive the lower end of a lever 19. The lever 19 is suitably secured to shaft 18 so that these parts do not have relative movement, the upper end of lever 19 being pivotally connected by a pin 89 to the rear end of arlink 8|.

When the link 81 is moved so as to swing the lever 19 about its pivot provided by shaft 18, the

quadrant gear 16 will also be rotated to: move the rack 14 in thecylindrical guide 15. Reciprocating movement of rack 14 causes rotary movement of shaft D by reason of the gear teeth 13, it being apparent that by suitable adjustment of lever 19 the various racks 61, 68, 69 and 10 may be selectively rotated into engagement with the` corresponding segmental gears 65, 659, 65D, and 49. It will also be apparent that in any position of selective rotary adjustment of t-he shaft D, this shaft may be moved axially by a mechanism which will be presently described; ,the gear teeth 13 sliding along the rack 14.

We have provided fluid pressure operatedl means for selectively adjusting lever 19, this adjusting means as best shown in Figs. 1, '1, and 8 comprising a leader valve mechanism E and the manual controls F and G.

The leader valve mechanism E is carried in a casting 82 suitably secured by the fasteners 83 to the transmission cover 59. The casting 89 has upper and lower communicating spaces or chambers 99 and 85, respectively, the chamber 81 receiving a gear 8S rotatably supported on a shaft 81 to which is non-rotatably secured a lever 99, this lever projecting upwardly from the outside of the casting 92 as shown in Fig. 2. The upper end of lever 99 is pivotally connected by a pin 89 to the forwardly extending end of the aforesaid link 91 from which it will be apparent that rotation of gear 89 will swing the lever 98 about the center of shaft 81, the link 91 causing a corresponding swinging movenent of lever 19.

Engaging the gear 99 is a rack 99 disposed intermediate the openings 99 and 85. This rack is formed with piston portions 91 and 92 at its opposite ends, these piston portions being slidably guided in the co-axial cylinders 99 and 99.

Operating below the rack 99 is a leader valve 95 formed with end piston valve portions 99 and 91 respectively slidable in the cylindrical. guides 98 and 99. The valve 95 has a passage 199 extending axially therethrough, the cylindrical valve 1 guides 9B and 99 thus being. in communication through the leader valve 95. The cylinders 99 and 98jare in communication by a vertical passage 191 and a similar passage 192 which places the cylinders 91 and 99 in communication.

The leader valve 95 is formed with an intermediate rack portion 1x93 engaged by a gear 191, this gear also meshing with the teeth of rack 99. The gear 194 is mounted on the upper end of a lever 195 pivoted at 199. A second lever 191 extends downwardly from the pivot 196, levers 195 and 191 being secured together against their relative rotation. The gear 194 is suitably journaled on lever 195 so that as the lever is rotated about its pivot 196 the gear\194 will follow the lever movement, it being understood that the gear axis will move a small amount axially of lever 195 during the swinging movement of the lever inasmuch as the gear 191 is constrained against orbital movement about the p11/ot 199 by reason of its engagement between the racks 99 and 193.

'I'he cylinderc 98- is in communication with a conduit 199 through which a suitable fluid such as oil under pressure is supplied to the cylinder, the chamber 85 opening downwardly to a conduit 199 for returning the fluid to the oil reservoir or sump as will be presently apparent.

Connected to the downwardly extending end of lever 191 is a suitable linkage such as a Bowden wire mechanism 1 19 which, as best shown in Fig. l, extends to a point for convenient manipulation by the motor vehicle driver. In Fig. 1 we have vto a selector segment II3, this segment being securely mounted by a bracket I|4 to the usual steering post I|5 carrying the vehicle steering` wheel I'II. The segment |I3 is provided with a flange formed with a series of notches or stops |,I1, II8, I|9, |20, and I2I, these notches being adapted to selectively receive the selector arm I I as the arm is manually manipulated about its pivot II2. lIn order to prevent accidental displacement of the arm II I from engagement with any of these notches, the selector arm III may have a certain amount of vyielding whereby the selector arm is sprung as the arm is Alifted from one notch and moved into engagement with another of the notches. When the selector arm III is in engagement lwith the notch |20 the transmission is in neutral so that no drive will be transmitted from engine A to the power take-` off shaft I0 and for convenience of reference the notch |20 may be Vtermed as the neutral notch. In a corresponding manner the notch I|1 is the rst speed notch, the notch |I8 is the second speed notch and the notch I I9 may be termed the third or direct speed notch. 'Ihe notch I2I is the reverse notch, it being understood that when the selector arm III is engaged with the reverse notch I2I, the transmission will be manipulated under controls which will be presently apparent for driving the power take-off shaft I0 in the reverse direction.

Before describing the means for controlling a supply of fluid under pressure to the passage |08 and the means for axially reciprocating the shaft D, we will describe the operation of the leader valve device E in response to manual manipulation by the selector arm II I. AIn Fig. 8 the levers 19 and 88 are illustrated in the positions which they occupy when the shaft D is rotated to bring the second speed rackS into engagement with the segmental gear D for actuating the second speed braking device 23. Assuming that the parts are in such position with the shaft D moved axially to the left as viewed in Fig. 2 so as to contract the band 26 of the second speed braking device 23, it will be apparent that the forces required to maintain the band in the contracted position will hold the levers 8`8 and 19 in the position shown in Fig. 8, the gear being also held against rotation. In this manner the rack is also held against axial movement in ,response -to operation of the lever .|05 in the following manner. In Fig. 8 (also in Figs. and 9) we have illustrated a number of radial lines respectively designated as 'I, 2, 3, N and R, these lines representing the axial position of link |05 when the selector arm III is engaged with its notches II1, IIB, II9, |20, and I2I, respectively. Thus the letter N indicates the neutral position of lever |05, R. represents the reverse position thereof, and

the numerals I, 2, and 3 indicates the first, sec` ond and third speed positions of lever |05.

In Fig. 8 the lever |05 has been moved from its position indicated by the line 2 to its third speed position indicated by the lineA 3, the selector arm III having been moved from the, second speed notch .I I8 into engagement with the third speed notch |I9. During this connterclockwise rotation of lever |05 the rack 90 remains stationary as previously explained, the gear |04 during this movement of lever |05 is given a clockwise .rotation by rack 90, such rotation acting through the rack |03 to move the leader valve 95 to the left and into the position illustrated in Fig. 8. In such position it will be apparent that the fluid pressure delivery conduit |08 is placed .in registration with the vertical passage |02, the piston valving portion 91 having uncovered the lower end of the passage |02. i

When the fluid pressure is admitted to the confduit |08 as will be presently apparent, the fluid pressure passes through the valve passage |00 and thence to the passage |02 and cylinder 94 where the fluid pressure acts on the cylindrical end 92 of the rack 90. Prior to admission of the iiuid pressure to the passage |08 the shaft D is preferably moved rearwardly to release the second speed braking device 23. The leader valve is balanced with respect to the action of the fluid pressure which acts on the piston portion 92 to move the rack 90 forwardly or to the left as viewed in Fig. 8. This forward movement of rack 90 performs two functions. First, the rack 90 acts through gear |04 (the lever |05 being held stationary by engagement of the selector arm III in the notch |I9) to move the leader valve 95 rearwardly or to the right until the piston valving portion 91 again closes communication between the passage |02 and the cylinder 99. Second, the aforesaid forward movement of rack 90 acts through gear 86, lever 88 and link 8 I` to swing the lever 19 clockwise to rotate the shaft D clockwise as viewed in Fig. 3. In this manner the second speed rack 69 is rotated free from engagevment with the second speed segmental gear 65h l justment' of the leader valve 95 from the second speed position into the third speed position, it will be apparent that with any of the speed ratio controlling devices 22, 23, 24, or 25 in actuation the selector arm III may be manipulated into engagement with any of the notches of segment n I I3 to adjust the lever |05 and the leader valve 95 in advance of a gear ratio change in the transmission C. Thus, a preselection of a gear ratio may be obtained and in any instance the rack 90 will'be moved either forwardly or rearwardly an amount corresponding to the manual adjustment of leader valve 95, the latter being returned 1 to the Fig. 1 position when the rack 90 is moved by the fluid pressure. It will therefore be apparent that it is not necessary for adjustment of the selector arm III into successive notches of the segment I I3. For example, the selector arm I II may be moved directly from the first speed notch II1 into engagement with the third speed notch I I9 in which event the transmission will be adjusted directly from the drive through the rst speed braking device 22 to a drive through the third or direct speed braking device 24.

When the selector arm III' is engaged in the neutral notch |20 the neutral space 1| indicated in Fig'. 3 for the shaft D win be brought opposite the segmental gears 55 and 85, it being apparent that under such conditions axial movement of the shaft D will not actuate any of the braking devices.

When the operator'desires to drive the motor vehicle in reverse, the selector arm III is moved into engagement with the 'reverse notch 2| and rack 61 thereof with the segmental gear 65.

We will next describe the manually controlled fluid pressure operating means for admitting fluid pressure to the conduit |08 and also for reciprocating the shaft D in order to successively actuate and release the various speed ratio controlling 10 devices 22, 23, 24, and 25 of transmission C.

In Figs. 1 and 2 it will be noted that the transmission is provided with a reservoiry or sump |22 for storing a supply of a suitable fluid such as oil.`v This oil is preferably maintained in the reservoir |22 separate from the oil used for lubricating purposes in the reservoir |23 (see Fig. 3) for lubricating the various parts of the transmission gearing and actuating mechanism illustrated in Fig. 3. However, if desired, the same oil may be used for lubricating the transmission parts and also for the pressure medium adapted to operate the leader valve mechanism E and the shaft D.

Referring now to Fig. 2 the sleeve |9 which is drivingly connected to engine A through the in- 25 termediary of the driving clutch member has secured thereto a driving gear |24 meshing with a driven gear |25. 'Ihe gear |25 is suitably arranged to drive a pump F of any type suitable for placing the fluid medium employed under the idesired pressure. Where oil is employed as the fluid pressure medium we may arrange the pump F for placing the oil under a pressure of approximately five hundred pounds although obviously this may vary within wide limits depending upon the sizes of the various plungers, pistons, and the like operated by the oil and also by the capacity and power transmitted in any particular transmission system. By driving the pump F directly from the engine A rather than from the mechanism driven thereby, the pump F will operate to maintain the -uid medium under pressure even when the engine is idling, this being a desirable condition in the power transmission system.

The pump F is adapted.to draw its working medium from the reservoir |22, the oil being discharged from the pump under the desired pressure through a delivery conduit |26 to a passage |21 formed in the valve casting |28. This casting has branch passages |29 and |30, best seen in Fig. ,1, in communication with the passage |21. Controlling the passage ofthe oil along conduits |29 and |30 is a valve |3| formed with the reduced valving portions |32 and |33 respectively adapted for alignment with the passages |29 and V |30 for selectively permitting the oil pressure to pass along the passages.

The valve |3| is yieldingly urged upwardly to the normal position thereof illustrated in Fig. 9 by a spring |34 and the valve has its lower end formed with a longitudinal passage |35 opening downwardly to the aforesaiddischarge conduit |09 which extends beyond the valve for discharging the oil back' to the reservoir |22. The valve passage |35 extends upwardly and laterally thereof as indicated at |36 so that asillustrated in Fig.

9 when the valve |3| is in its normal upward position, the portion of the passage |30 rearwardly of valve |3 (the valve at such time closing the portion of the passage |30 between the pump F and the valve) is in communication with the return passage |09.

When the valve |3| is in its lowered position as illustrated in Fig. 7 the branch passage |29 is closedby the valve, the branch passage |30 is opened by reason of the reduced valve portion |33,

Iating in the cylinder lower extension |52.

and the va1ve` passage |35 is out of communication with the passage |30 since the entry portion |36 of the passage |35 is lowered below the passage |30.

We prefer tocontrol the reciprocation of valve 5 |3| by a manual means rather than to have the operation of valve |3| automatically responsive to other controls of the mechanism. Thus, the upper end of the valve is extended through the casting |28 for operating engagement with a lever' l0 |31 mounted on a rock shaft |38, the rock-shaft having secured thereto a second lever |39 connected to a linkV |40 for pivotal connection at |4| to a bell crank lever |42 pivotally supported at |43 to a bracket |44. This bracket is suitably 15 secured at a convenient point such as to the usual vehicle toe board |45. The bell crank lever 42 is operated by a rod |46 pivotally connected thereto at |41 the rod extending upwardly through the toe board |45 to the foot pedal or button |48, the 20 mechanism between this pedal and the valve 3| comprisingy the aforesaid manually operating means G.

In Fig. 9 the pedal |48 is shown in its normal upwardv position with the valve 3| move'd up- 20 wardly by the inuence of spring |34. In Fig. 7 it will be noted that the pedal |48 is shown in its downward or actuated position for lowering the valve |3| into the position illustrated.

Referring particularly to Figs. '1 and 9 we have 30 provided a fluid pressure operating cylinder H open at the upper end thereof to the passage |29 whereby oil pressure from pump F will be delivered to the cylinder H when the valve 3l is in the Fig. 9 position. 35

Operating within the cylinder H is a piston |49 having a downwardly extending rod structure |50 yieldingly urged downwardly bya spring |5| oper- The spring |5| reacts against a xed plate |53 through 40 which the piston rod |50 slides, the plate |53 bearing upwardly against a shoulder |54 provided by the cylinder H.

The rod |50 has a transversely slotted opening |55 receiving the forwardly extending end of a 45 lever |56 pivotally carried `by a shaft 51, the shaft and lever being connected against relative rotational movement. Secured to shaft |51 is a gear segment |58 meshing with the piece of a rack |59 formed on the shaft D forwardly of the third 50 speed rack 10 as best seen in Fig. 2.

'Ihe lever |56 together with the gear segment |58 and the rack |59 provides the means for imparting the reciprocating movement to the shaft D for selectively operating and releasing the 55 various braking devices 22, 23, 24, and 25. In Fig. 7 it will be noted that the lever 56 is shown in its upward swinging movement whereby the shaft D is in its rearward movement of Fig. 2, the braking devices being released for this position of 60 shaft D. In Fig. 9 it will be noted that the lever |56 is in its lowered position having moved the shaft D forwardly for causing operation of one of the braking devices through operation of one of the racks of shaft D in engagement with the cor- 65 responding gear segment associated with one of the braking devices.

The upper end of vcylinder H adjacent the delivery end of the passage 29 is provided with a port |60 normally establishing communication be- 70 tween cylinder Hand a surge chamber or passage |6|. The surge chamber |6| extends upwardly fromV the port |60 so as to store a quantity of oil displaced by upward movement of the piston |49 for reentryto the cylinder H during the rst part of the downward movement' of the piston as will be presently more readily apparent. As bestl shown in Figs. 2 and 7 the surge chamber |6| has an outlet passage |62 extending through the side wall of the transmission casing, this wall having an opening |63 communicating with the passage |62 so that anyexcess oil displaced by upward movement of piston |49 will pass from the surge chamber |6| through the passage |62 and opening |63 1for delivery intothe reservoir |22.

According to the normal position of the parts as illustrated in Fig. 9 the port |60 is closed by a valve |64 yieldingly urged toward port |60 by a spring |65, the valve having a hollow stem |66 communieating with cylinder H by a check valve |61 yieldingly urged upwardly to close the opening |68 of the valve stem |66 by reason of a spring |69. The valve stem |66 has a discharge or pressure relief port |10 for establishing communication between cylinder H and the chamber |6| when the check valve |61 is displaced downwardly from the position thereof illustrated inFig. 9 to the Fig. 7 position. For controlling the displacement of the check valve |61 we have provided a plunger |1| slidable in the opening |68 of valve stem |66, this plunger having a head |12 normally spaced slightly above the upper end of the valve stem I 66 as shown in Fig. 9, the check valve J|61 in such instance being seated upwardly toclose communication between cylinder H and the surge chamber |6|.

Operating against the head |12 is a lever arm |13 pivotally connected at |14 with a link |15, this link extending downwardly for pivotal connection |16 withthe aforesaid lever |56. The lever arm |13 has a second lever arm4 portion |11 extending rearwardly of the pivotal connection |14, the lever arm |11 being pivotally connected at |18 with a piston valve |19 slidably guided in a cylinder |80. The cylinder has its lower end in communication with the aforesaid oil pressure delivery conduit or passage |30 whereby the oil pressure delivered by pumpF will, when valve |3| is raised to the Fig. 7 position, enter the cylinder |80 and act to move the piston valve |19 upwardly in the cylinder |80. The cylinder |80 has a lateral port |8| in. communication with the aforesaid passage |08, the arrangement being such that the lower end of the piston valve |19 is normally spaced below the port |8| as shown in Fig. 9. When the piston valve |19 is in its uppermost position as illustrated in Fig. '1 it will be apparent that the piston valve has uncovered the port |8| so as to establish communication between the oil pressure delivery -conduit |30 and the passage |08 extending to the leader valve mechanism E.

In operation of the power transmission mechanism as thus far described we will describe the operation of y-tl'ie mechanism between a typical speed ratio change as a change from the second speed to the third speed by way of example.- Let it be presumed that the motor vehicle is being driven in the second speed with the selector arm in-engagement with the second speed notch',

` I|8 of the segment H3. Under such conditions of drive the pedal las wnib in its upward posiltion of Fig. 9 and the valvev |3| will be raised by the spring |34 into the Fig. 9 position thereby causing the pump F to deliver iluid pressure through the branch passage |29 to the cylinder H, the branch passage |30 being closed by the valve |3| according to the position of these parts as illustrated in Fig. 9. Thus, the piston |48 beratio and prior 1| it will be apparent that the levers 08 and 19 ing in its downward position under the influence .of spring |5|`and the uid pressure above the piston, the lever |56 is lowered and the gear segment |68 and rack |69 will hold the shaft D in the forward position. With the drive taking place in the second speed ratio, the forward position of shaft D has caused the second speed rack 69 to operate through the gear segment 65b to contract the brake band 26 of the second speed braking device 23 thereby causing the drive to take place through the transmission in the second speed ratio.

From Fig. 9 it will also be apparent that the piston valve |19 is in its lowermost position and the fluid pressure in cylinder LH will lhold the valve |64 against the port |60. The head |12 of plunger |1| is slightly spaced above the stem |66 of valve I 64 permitting the spring |69 together with the uid pressure in cylinder H to hold the check valve`|61 against its seat for closing communication between cylinder H and the surge 'chamber |6|.

, With the drive taking place in the second speed to movement of the selector arm will occupy the positions illustrated in Fig. 8 although the lever |05 will lie' in the direction of the radial line 2 and the leader valve 95 will occupy its normal position illustrated in Figs. 7

and 9 wherein the piston valving portions 96 and 91 close the lower ends of the passages |0| and |02. v

With the parts in the positions described the motor vehicle maybe driven as long as desired in the second speed ratio. For purposes fof illustration let it be presumed that the vehicle driver desires to manipulate the transmission mechanism into the third speed or direct drive for the motor vehicle. In order to eect this change in the driving speed ratio, the driver first moves the selector arm from engagement with the second speed notch IIB into engagement with the third speednotch ||9, this being the position of the selector V-armas illustrated in Fig. l. This movement of'J the selector arm will operate the leader valve 95 into its position illustrated in Fig. 8 according to the foregoing detailed description of the operation of the leader valve, it being apparent that the rack will be fixed against movement since the iiuid pressure is still operating in cylinder H against the piston |49 to hold the shaft D in its forward position. Thus, we have provided a preselector arrangement whereby the selector arm may be adjusted into a new position of transmission control in advance of a change taking place in the transmission.

At such time as the vehicle driver desires the change from the second speed ratio into the thirdvor direct speed ratio to take place, he momen- 'tarily depresses the pedal |48 with his foot and` the fluid pressure operating mechanism respondsl as follows. Depressing the pedal |48 moves the valve |3| downwardly from the Fig. 9 into the Fig. '1 position thereby closing the branch passage |29 and opening the .branch passage |30 to the cylinder |86. The uid pressure thus acts lon the piston valve |18 to move the piston valve thereby unseating the check valve |61 to relieve the pressure of the oil above the piston |49. Continued upward movement of the piston valve |19 causes further downward movement of the swinging arm |13 and, since the relatively high oil pressure in cylinder H has been relieved through the discharge port |19, the plunger head |12 moves downwardly as a unit with the valve stem 66 causing the valve |64gto move away from the port i60 against the action of spring |65. At this time of the operating cycle the piston valve 119 has moved upwardly but has not yet uncovered the port 8| for causing operation of the leader valve 95, When the valve |64 has been l5 unseated as aforesaid continued upward movement of the piston valve |19 will cause the lever portions |13 and |11 to swing upwardly about the forward end of the lever portion |13 as a. fulcrum inasmuch as at such time the lever arm 20 113 has moved downwardly to its limiting position determined by engagement of the head |12 against the upper face of a bushing 182. As the lever arms 113 and |11 swing upwardly as a unit about the head 112 as a fulcrum point, it will be apparent that the pivot 114 will be swung upwardly causinglink 115 to also move upwardly. This upward movement of link 115 will-act to swing the lever |56 upwardly about 'the axis of the pivotal supporting shaft 151 for moving the piston 149 upwardly in cylinder H and compressing the spring 151. Simultaneously therewith the segmental gear |58 will be rotated clockwise as viewed in Figs. 7 and 9 to act on rack 159 for moving the shaft D rearwardly to release the second speed braking device |23.

As the piston |419 moved upwardly as aforesaid the fluid above the piston will be displaced past the valve 188 and port 1611 into the surge chamber |81, any excess uid passing through the passage 152 and opening |83 for discharge into the reservoir |22. However, an appreciable volume of the oil will be stored in the surge chamber 181 for reentry into the cylinder H as will be presently apparent.

During the latter part of the upward swinging movement of the lever arms |13 and 111 to raise the piston |49, the piston valve 119 will move upwardly to the limit of its travel thereby uncovering the port 18| and. causing the fluid pressure from passage 131| toenter the passage |08. This fluid pressure then acts on the leader valve 95 as hereinbefore described in detail to move the leader valve from the Fig. 8 position into the position thereof shown in Fig. 9. This movement of the leader valve causes adjustment of the rack 90 whereby the lever 88 together with the lever 19 is moved from the second speed position thereof illustrated in Fig. 8 into the third speed position shown in Fig. 7. While the entire cycle of gear change preferably takes place in a relatively small amount of time such as a fraction of a second, the leader valve mechanism E does not respond to the upwardmovement of the piston valve |19 as quickly as the upward movement of piston |49 so that by the time the lever 88 is swung by the rack 99 into its new position in response to return of leader valve 95, the piston |49 has moved upwardly to the limit of its travel for operating the shaft D to its rearward-position. Thus, when the rack D is rotatably adjusted in response to Va swinging movement of lever 88 to bring the third speed rack 10 into alignment with the third speed gear segment 65, the second speed braking device 23Y has been fully released.

ready for swinging operation when the shaft D.

is returned to its forward position for operating the third speed braking'device 24.

When the operator releases the pedal |48, the valve |31 will `be restored to its normal upward l5 position under the inuence of spring |34, closing off the branch passage |39 from communicationwith the cylinder |811 and again opening the branch passage 129 `to the cylinder H. As soon as the uid pressure has been cut off from the 20 cylinder |89, the spring 151 acts to move the piston 149 downwardly, the oil stored in the surge chamber |81 quickly flowing into the cylinder H` above piston |49. Such arrangement avoids the necessity for the pump F to supply suicient oil 25 to the cylinder H to produce the desired displacement of piston 149, the pump F mainly being called upon to build up the pressure in the cylinder H after the fluid in thesurge chamber 151 has been drawn into the cylinder H pursuant 30 to downward movement of piston 149. Such arrangement materially reduces the time necessary for completion of the cycle of the fluid pressure operating mechanism.

The lever 151i follows the piston 1119 in its 35 downward movement, the link acting on the lever portion |13 togswing the lever arms 113 and 111 downwardly about the head 112 as a fulcrum, the piston valve 119. moving downwardly in the cylinder 189. The oil displaced by the downward 40 movement of the piston valve returns'to the reservoir |22 by reason of the passages 138, 135 in the valve |91.

As the lever 155 moves downwardly it will be apparent' that the gearsegment 158 will rotate 45 counterclockwise causing \the rack |59 to move 4forwardly. Inasmuch as the valve 1811 will bey seated by the spring immediately after the fluid in the surge chamber 18| enters the cylinder H, the fluid pressure in cylinder H Will rapidly 50 build up under delivery of oil from the pump F and the piston |49 will then operate under the combined influence of the oil pressure and the action of spring 15| to cause the third speed rack 111 to move Aforwardly with the shaft D to 55 swing the lever 45 and thereby operate the third speed braking device 24. It will also be apparent that` the fluid pressure building up in cylinder H will cause the checkv valve 165 to seat and to thereby restore the plunger 111 to the normal 60 position illustrated in Fig. 9. While the check valve 161 may be seatedduringthe latter part of the downward movement of piston |49, the fact that the check valve 161 may be unseated during the initial downward movement of the piston will 65 not materially prevent the desired rapid build- `ing up of the oil pressure in cylinder H inasmuch as the delivery of pump F is adequate to build up theV pressure more rapidly than the tendency for the fluid pressure to fall off past the check valve |81.

We have described a'complete cycle of opera tion of the power transmission mechanism., it being apparent that a similar cycle takes place wwhenever the vehicle operator manipulates the selector arm from one of the notches of segment ||3 to another position of control followed by a momentary actuation of the pedal |48. It will furthermore be apparent that it is not necessary for the vehicle driver to follow the sequence of thel notches of segment ||3 since the selector arm may be moved directly from engagement'with one of the notches thereof into another notch remotely spaced from the position of initial engagement. Thus, by way of example, when the selector arm is engaged with the neutral notch |20, the operator may move the selector arm directly into engagement'with the seconder third speed notches ||8 or ||9 respectively.

When the selector arm is moved into engagement with the neutral notch I 20 followed by a momentary depression of the pedal |48, the shaft D is thereby moved rearwardly to release any of the braking devices which may have been in operation, the forward movement of the shaft D being free from operating engagement with any of the braking devices through the provision of the neutral space 1| referred to in detail hereinbefore.

When the operator desires to drive the motor vehicle in reverse, he adjusts the selector arm into engagement with the reverse notch |2| of segment |'|3 and, when the pedal |48 is momentarily depressed, the cycle of operation of the fluid pressure mechanismA will be apparent from the specic example given above, the reverse rack 61 in such instance operating through the reversing gear segment 65 to operate the reverse speed ratio controlling device 25. v

In order to limit rotation of the various screw shafts 6U, 68a, and 60h when the shaft D is operated rearwardly in releasing the respective braking devices 25, 22, and 23 and to thereby maintain proper alignment for entry of the teeth of racks 61, 68, and 69 with the respective segmental gears 65, 65a, and 65h, each of the aforesaid screw shafts is provided with an upward extension |83 illustrated in Figs. 3 and 4. Secured to the side cover 58 by fasteners |84 lisabracket |85 provided with a series of longitudinally spaced openings |86 through which the respective projections |83 extend. vIn Fig. 4 the splines |81 between the bracket 52 and the various nuts 56 are also illustrated. During the rearward releasing movement of shaft D, whichever of the screw shafts 88, S or 6|!b is engaged with shaft D is rotated substantially ninety degrees to position the shaft extension |83 in the limiting releasing position as shown in Fig. 4. When either of the screw shafts, is operated by forward movement of shaft D so as to rotate any of the screw shafts in a clockwisedirection as viewed in Fig. fl, the projection |83 of such screw shaft is rotated through substantially ninety degrees within the associated opening |86 of the bracket |85. In this manner proper alignment is maintained between the racks 61, 68, and 69 with the teeth of the associated segmental gears 65, 65, and 65b respectively.

In order to prevent any possibility of the shaft D being moved forwardly to engage more than one of the racks thereof with the respectively associated segmental gears for operating the various braking devices, and ,also for maintaining the desired alignment of the shaft D with respect to the associated segmental gears operated thereby we have provided the mechanism illustrated in Figs. and 6. The shaft D has a bearing portion adjacent the forward end of the circular rack 13, this bearing portion being slidable through a xed bushing |88 formed with a series of circumferentially spaced, longitudinally extending rearwardly opening slots |89, |90, |9|, |92, i

and |93. These slots respectively and selectively receive the end |94 of a pin |95 xed within a transversely extending openingl |96 of the shaft D.

In Figs. 5 and 6 the pin end |94 is illustrated in alignment with the third speed slot |9| corresponding to the position of shaft D illustrated in Fig. 2. When the shaft D is moved forwardly as viewed in Fig. 2` or to the right as viewed in. Fig. 6, the pin end |94 will move in the slot |9|, the bushing |88 having been previously adjusted with respect to shaft D so that the various slots of bushing |88 will assure the proper alignj ment of shaft D and to also prevent forward movement of the shaft unless the pin end |94 is properly aligned with one of the slots of the bushing |88. In this manner forward movement of shaft D is prevented in the event that the shaft i is not properly adjustably rotated by the leader valve selecting mechanism E.

When the shaft D is rotated into its position for actuating the first speed braking device22 the pin end |94 will be aligned with the first speed slot |89 of the bushing |88. In similar manner the slot |98 is the second speed slot, slot |92 is the neutral slot, and slot |93 is the reverse slot as will be readily understood.

The rearwardly extending faces |98 of bushing |88 between adjacent slots thereof is preferably sloped circumferentially and forwardly toward the adjacent slots to guide the pin end |94 into the proper slots of bushing |88 in the event that the shaft D isslightly misaligned from the slot.

, In Fig. 6 the shaft D is illustrated in the rearmost position of movement determined by the screw shaft projection |83 and the associated bracket |85, a relatively small amount of clearance |91 being provided between the pin end |94 `clearance |91 representing substantially the forward movement of shaft D in taking up the clearancebetween the brake b-and 426 of any of the braking devices and the rotary drum associated therewith.

Various modifications and changes will be apparent from the teachings of our inventiongasy set forth in the appended claims and it is not our intention to limit our invention to the particular details of construction and operation shown and described for illustrative purposes.

What we claim is:

l. In a motor vehicle transmission having a plurality of speed ratio controlling braking devices, means operably associated with each of said controlling devices for actuating said braking devices, an adjustable rack shaft adapted for selective operative connection with said actuating teeth.

devicesfor actuating said devices, an adjustable l shaft having a plurality of racks respectively adapted for selective operative connection with said actuating means for said controlling devices, manually operated means for rotating said shaft for selectively operably connecting said racks respectively with said actuating means, and power operating means for axially actuating said shaft.

4. In a motor vehiclevtransmission having a' plurality of speed ratio controlling devices, means operably associated with each of said controlling devices for actuating said devices, an adjustable shaft having a plurality of racks respectively adapted for selective operative connection with said actuating means for said controlling devices, manually operated means for rotating said shaft for selectively operably connecting said racks rcspectively with said actuating means, and power operating means for reciprocating said shaft.

5. In a motor vehicle transmission having a plurality of speed ratio controlling devices, means operably associated with each of said controlling devices for actuating said devices, an adjustable operating element adapted for selective operative connection with said actuating means for said controlling devices, manually controlled uid pressure operating selector means for adjusting said operating element selectively to its positions of adjustment subsequently to manual selection of said selector means, and power operating means for alternately actuating and releasing said operating element, said fluid pressure operating selector means acting to adjust said operating element in response to release thereof.

6. In a motor vehicle transmission having a plurality of speed ratio controlling devices, power operated means for selectively operating said controlling devices, and manually operated means for selectively controlling operation of said controlling devices by said power operated means, said manually operated means including a rack shaft adjustable to selectively establish an operating connection between said power operated means and said controlling devices, said rack shaft having a plurality of groups of rack teeth carried thereby for providing said operating connection.

'7. In a motor vehicle transmission having a plurality of speed ratio controlling devices, power operated means for selectively operating said controlling devices, and manually operated means for selectively controlling operation of said controlling devices by said power operated means, said manually operated mans including a rack shaft adjustable to selectively establish an operating connection between said power operated means and said controlling devices, said rack shaft having a plurality of groups of rack teeth carried thereby for providing said operating connection, said power operated means acting through said rackshaft to selectively operate said controlling devices by said groups of rack 8. In a motor vehicle transmission having a plurality of speed ratio controlling devices, power operated means for selectively operating said controlling devices, an adjustable element adapted to selectively establish an operating connection between said power operated means and said controlling devices, and manually controlled uid trains and rotary controlling drums associated therewith, braking means for resisting rotation of each of said drums, means operably associated with each of said braking means and adapted to actuate the respective braking means, an adjustable rack shaft adapted for selective operative connection with said actuating means, manually operated means for selectively adjusting said rack shaft, and power operating means for actuating said rack shaft. y

10. In a motor -vehicle planetary transmission having a plurality of speed ratio planetary gear trains and rotary controlling drums associated therewith, braking means for resisting rotation of each of said drums, means including a gear associated with each of said brakingmeans and adapted to actuate the respective braking means,

an adjustable shaft having a plurality of racks respectively adapted for selective operative connection with said actuating means, manually operated means for rotatably adjusting said shaft to selectively engage said racks with said gears respectively, and power operating means for alternately reciprocating said shaft to selectively actuate and release said braking means.

11. In a motor vehicle planetary transmission having a plurality of speed ratio planetary gear trains and rotary controlling drums associated therewith, braking means for resisting rotation of each of said drums, means operably associated with each of said braking means for actuating said braking means, an adjustable operating element adapted for selective operative connection with said actuating means, manually controlled fluid pressure operated means for selectively adjusting said operating element, said fluid pressure means including a leader valve, and power operating means for actuating said operating element.

12. In a motor vehicle planetary transmission having a plurality of speed ratio planetary gear trains and rotary controlling drums associated therewith, braking means for resisting rotation of each of said drums, a shaft for each of said braking means, each of said shafts having opposltely threaded portions, means threadedly connected to said threaded portions of each of said shafts and adapted on rotation of said shaftsto actuate the braking means respectively associated therewith, power operating means for actuating said shafts, and manually operatedv means for selectively controlling actuation of said shafts by said power means.

13. In a motor vehicle planetary transmission having a plurality of speed ratio planetary gear trains and rotary controlling drums associated therewith, braking means for resisting rotation of each of said drums, a shaft for each of said braking means, each of said shafts having oppositely threaded portions, means threadedly connected to said threaded portions of each of said shafts and adapted on rotation of said shafts to actuate the braking means respectively associated therewith, a gear carried by each of said shafts, an adjustable rack shaft adapted for selective operable connection to said gears, manually controlled selector means for selectively adjusting said rack shaft, and power means for actuatingsaid rack shaft in its positions of adjustment for selectively operating said braking' means.

14. In a motor vehicle transmission having a plurality of speed ratio controlling devices, means operably associated with each of said controlling devices for actuating said devices, an adjustable reciprocatory operating element adapted for selective operative connection with said actuating means for said controlling devices, manually controlled means for selectively adjusting said operating element, fluid pressure operating means for actuating said operating element by uid pressure force application in each direction of reciprocation of said operating element, and means for controlling fluid pressure supply to said fluid pressure operating means.

15. In a motor vehicle transmission having a plurality of speed ratio controlling devices, means operably associated with each of said controlling devices for actuating said devices, an adjustable operating element adapted for selective operative connection with said actuating means for said controlling devices, manually controlled means for selectively adjusting said operating element, a cylinder, a piston operating in said cylinder,

means operably connecting said piston and said operating element, means for admitting a uid under pressure to said cylinder for causing said piston to actuate said operating element in one direction of movement thereof, and uid pressure means for restoring said piston to thereby actu- -ate said operating element in a. direction substantially opposite to that aforesaid.

16. In a motor vehicle transmission having a speed ratio controlling device, a uid pressure receiving cylinder, a piston operating in said cylinder, means actuated by said piston duringy the working stroke thereof for operating said controlling device, means for supplying 'fluid under pressure to said cylinder, and means including a chamber adapted to receive fluid from said cylinder during the return stroke of said piston and to return said fluid to said cylinder during the said Working stroke of the piston, and means for operating said piston on its said return stroke.

17. In a motor vehicle transmission having a speed ratio controlling device, a cylinder having a uid pressure receiving space, means including a piston operating in said space for actuating said controlling device, means for supplying iiuid pressure to said space to operate said piston, and means for accelerating the pressure rise in said cylinder space over the pressure rise produced by said uid pressure supply, said last named means including a force applying element operably connected to said piston throughout the iiuid pressure stroke thereof. n

18. In a motor vehicle transmission having a plurality of speed ratio controlling devices, means operably associated with each o f said controlling devices for actuating said devices, an adjustable operating element adapted for selective operative connection with said actuating means for said controlling devices, manually operated means for selectively adjusting said4 operating element, DOWeI' Operating means for actuating said operating element, and means for adjusting said operating element to supplement the adjustment thereof by said manually operated means whereby to compensate formisalignment in the operative connection between said operating element and the actuating means for said controlling devices.

19. In a motor vehicle planetary transmission having a plurality of speed ratio planetary gear trains and rotary controlling members associated therewith, a brake for each of said members, brake applying means for each of said brakes, an adjustable operating shaft adapted to be selectively operably connected to said brake applying means for applying said brakes, said operating shaft extending generally longitudinally of the transmission adjacent said brake applying means, manually controlled means\ for selectively adjusting said operating shaft to provide said selective operative connection with said brake applying means, and power applying means for operating said shaft in its said positions of selective adjustment whereby to transmit braking lforce selectively to said brakes.

20. A transmission according to claim 19 wherein said operating shaft is provided with a plurality of groups of teeth adapted to provide said selective operative connection with said brake applying means.

21. A transmission according to claim 19 wherein said operating shaft is provided with a plurality of groups of teeth adapted to provide said selective operative connection with said brake applying means, said groups of teeth being spaced from each other longitudinally and circumferentially of said operating shaft.

22. A transmission according to claim 19 wherein said power applying means includes a fluid pressure operated piston operably connected to said shaft.

23. A transmission according to claim 19 wherein means is provided for supporting and guiding said operating shaft for rotation thereof by said manually controlled means and for axial movement by said power applying means.

24. A transmission according to claim 19 wherein means is provided for supplementing said manual selective adjustment of said shaft, said supplemental adjusting means being adapted to insure selective operative connection with only one of said brake applying means at any time.

25. A transmission according to claim 19 wherein means is provided-to delay the selective adjustment 4of saidshaft in response to selective operation of said manually controlled means.

26. A transmission; according to claim 19.

wherein said manually controlled means includes a uid pressure operated learler valve device adapted to delay the selective adjustment of said shaft in response to selective operation of said manually controlled means.

27. In a motor vehicle transmission having a plurality of speed ratio controlling devices, means including an adjustable selector operating member adapted to selectively operate said devices, power applying means for actuating said member in its positions of selective adjustment, and manually controlled means including a fluid pressure operated leader valve mechanism adapted to selectively adjust said member.

28. In a motor vehicle transmissionvhaving a plurality of speed ratio controlling devices, means including an adjustable selector operating member adapted to selectively operate said devices, power applying means for actuating said member in its positions of selective adjustment, and manually controlled means including a uid pressure operated leader valve mechanism adapted to selectively adjust said member, said manually controlled means including a manually controlled mechanism adapted to effect sequential selective adjustment of said member under control of said leader valve mechanism and then actuation lof said member by said power applying means.

29. In a motor vehicle transmission having a plurality of speed ratio controlling devices, means including an adjustable selector operating member adapted to selectively operate said devices, fluid pressure operating means including a leader valve mechanism adapted to selectively adjust said operating member, manually operated means adapted to pre-set said leader valve mechanism in advance of said selective adjustment of said member, and lluid pressure operating means adapted to operate said member in its positionsA of selective adjustment.

30. In a motor vehicle transmission having a plurality of speed ratio controlling devices, means including an adjustable selector operating member adapted to selectively operate said devices, fluid pressure operating means including a leader valve mechanism adapted to selectively adjust said operating member, manually operated means adapted to pre-set said leader valve mechanism inadvance of said selective adjustment of said member, a piston valve controlling the supply of fluid pressure to said leader valve mechanism, and fluid pressure operating means adapted to operate said member in its positions of selective adjustment, said fluid pressure operating means including a piston operably connected to saidl member, and means operably connecting said piston to said piston valve.

31. In a motor vehicle transmission having a plurality of speed ratio controlling devices, means including an adjustable selector operating member adapted to selectively operate said devices, fluid pressure operating means including a leader valve mechanism adapted to selectively adjust said operating member, manually operated means adapted to pre-set said leader valve mechanism in advance of said selective acustment of said member, a piston valve controlling the supply of fluid pressure to said leader valve mechanism, fluid pressure operating means adapted to operate said member in its positions of selective adjustment, said iiuid pressure operating means including a cylinder, a piston in said cylinder adapted to operate said memberpmeans for supplying fluid under pressure to said cylinder, a valve controlling the escape of fluid from said cylinder, and means operably connecting said piston valve with said piston, said connecting means being adapted to operate said valve.

32. In a motor vehicle `transmission having a plurality of speed ratio controlling devices, means including an adjustable selector operating member adapted to selectively operate said devices, fluid pressure operating means including a leader valve mechanism adapted to selectively adjust said operating member, manually operated means adapted to pre-set said leader valve mechanism in' advance of said selective adjustment of said member, a piston valve controlling the supply of fluid pressure to said leader valve mechanism, fluid pressure operating means adapted to operate said member in its positions of selective adjustment, said Iiuid pressure operating means including a cylinder, a piston in said cylinder vadapted to operate said member, means for supplying fluid under pressure to said cylinder, av

valve controlling the escape of uid from said cylinder, means operably connecting said piston valve with said piston, said connecting means being adapted to operate said valve, a. second valve adapted to control the supply of fluid pressure to said cylinder, and means for actuating said second valve subsequently to said pre-setting of said leader valve.

33. In a. motor vehicle planetary transmission having a plurality of speed ratio planetary gear trains and rotary controlling drums associated therewith, braking means for resisting rotation of eachof said drums, a shaft for each of said braking means, each of said shafts having oppositely threaded portions, means threadedly connected to said threaded portions of each of said shafts and adapted on rotation of said shafts to actuate the braking means respectively associated therewith, an adjustable selector operating element adapted for selective operative connection with said shafts intermediate the threaded portions thereof, lpower operating means for actuating said selector operating element in its positions of selective adjustment, and manually controlled means for selectively adjusting said selector operating element.

34. In a motor vehicle planetary transmission having a plurality of speed ratio planetary gear trains and rotary controlling drums associated therewith, braking means for resisting rotation of each of said drums, a shaft for each of said braking means, each of said shafts having oppositely threaded portions, means threadedly connected to said threaded portions of each of said shafts and adapted on rotation of said shafts to actuate the braking means respectively associated therewith, power operating means adapted to selectively act on said shafts intermediate the threaded portions thereof for selectively rotating said shafts, and means for selectively controlling the operation of said power operating means on said shafts.

35. In a motor vehicle transmission having a plurality of rotary speed ratio controlling elements, means operatively engageable with' each of said rotary elements for eifecting a speed ratio drivel through the transmission, means including a rack operated pinion operably associated with each of said engageable means for effecting operation thereof, power operating means adaptedl to selectively actuate said engageable means and including a common selector operating toothed rack member, and means for selectively adjusting said rack member to selectively engage the teeth thereof with said pinions.

36. In a transmission, a brake controlled gear set, a.` displaceable element having a series of gear teeth, a gear toothed member. engageable with the teeth of said element for applying said brake, means for displacing said element to engage teeth of said member and element, and means for applying a braking force to said element.

37. In a motor vehicle transmission having a plurality of speed ratio controlling devices, a cylinder having a fluid pressure receiving space. a piston operable in said space, means operably ,connected to said piston for selectively operating said devices, manually controlled means for selectively controlling the operation of said devices by said piston operating means, a fluid pressure operated plunger, iluid pressureV relief valve means for said cylinder space, means operably connecting said plunger with said piston and with said relief valve means, and valve controlled means for selectively admitting uid under pressure to said cylinder space and to said plunger.

38. In a motor vehicle transmission having a plurality of speed ratio controlling devices, a cylinder having a fluid pressure receiving space, a piston operable in said space, means operably connected to said piston for selectively operating said devices, manually controlled means for selectively controlling the operation of said devices by said piston operating means, a fluid pressure operated plunger,4 fluid pressure relief valve means for said cylinder space, means operably connecting said plunger with said piston and with said relief valve means, and manually controlled valvlng means for selectively supplying fluid under pressure to said cylinder space while venting said plunger and supplying iiuid under pressure to said plunger, said plunger when operated by fluid pressure acting through said plunger connecting means to open said relief valve means for venting said cylinder space.

39. In a motor vehicle transmission having a plurality of speed ratio controlling devices, a cylinder having a fluid pressure receiving space, a piston operable in said space, means operably connected to said piston for selectively operating said devices, manually controlled means for se-Y lectively controlling' the operation of said devices by 1said piston operating means, a fluid pressure operated plunger, iluld pressure relief valve means for said cylinder space, means operably connecting said plunger with said piston and with said relief valve means, valve controlled means for selectively admitting uid under pressure to said cylinder space and to said plunger, and a spring yieldingly urging movement of said piston in its direction of fluid pressure actuation.

40. In a motor vehicle transmission having aplurality of speed ratio controlling devices, a cylinder having a fluid pressure receiving space, a piston operable in said space, means operably connected to said piston for selectively operating said devices, manually controlled iluid pressure .operated means for selectively controlling the operation of said devices by said piston operating means, a fluid pressure operated plunger, iluid pressure relief valve means for said cylinder space, .means operably connecting said plunger with said piston and with said relief valve means, valve controlled means for selectively admitting fluid under pressure to said cylinder space 'and to said plunger, and plunger controlled means for supplying fluid under pressure to said selectively controlling uid pressure operated means.

WILLIAM T. DUNN.

AUGUSTIN J. SYROVY. 

